Carburetor



Oct. 20, 1925' H. O. CRAM CARBURETOR Filed Sept. 22, 1920 2 Sheets-Sheet l Suuewiioz H. 0. Crown @35 h I 5 attozucZW Oct. 20, 1925 H. O. CRAM CARBURETOR Filed Sept. 22, 1920 2 Sheets-Sheet 2 8mm Q H. O. Cram To all whom it may concern:

UNITED STATES 1,551, 57 PATENT... OFFICE.

HARRY 0. cm, 01: BRIDGEPORT, CONNECTICUT.

CARBIII'IBJEHEOR.

Application filed September 22 1920. Serial No. 412,041.

, Be it known that I, HARRY O. CRAM, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Carburetors, of which the following is a specification.

This invention relates to carburetors, and particularly to that class of carburetors constructed to utilize the heat from the exhaust gases of the engine to assist in carburation, an object of the invention being to provide an improved, compact, and unitary carburetor of this class wherein the necessity 10f any auxiliary heatin chamberor heating element interposed etween the carburetor and the intake manifold is eliminated, and wherein the mixin' chamber is'so constructed as to permit improved control of the fuel and air to be mixed therein.

A further object of this invention is to produce a two-fuel carburetor of compact unit structure, requiring no more space than the average gasoline carburetor, andso constructed therefore, as to make it adaptable to the average internal combustion engine without requiring any changes in the engine construction.

A further object of this invention is to provide an improved carburetor wherein the heat froin the exhaust gases of the engine is directed around the mixing chamber, and

be obtained at all times wherein the 'air and fuel to be mixed are diverted into various parts of the mixing chamber, whereby proper carburation will under all operating conditions.

A further object of this invention is to provide a carburetor having a practical means for controlling, correcting and regulating the-"flow of hydrocarbon fuel through the fuel jet or spray nozzle. By means of adjustable externall readily manipulated or operated so as to raise or lower .the float chambers, and hence change the fuel level with respect to the fuel nozzle, thus increasing or'decreasing the flow of fuel through the fuel jet, flexibility of engine control and fuel economy are attained.

Other objects of this invention will appear during the course of the description, reference being had to the accompanying drawings forming part of this specification wherein like reference characters indicate "located float chambers corresponding parts in the several views and wherein Fig. 1 is a front side elevation of a preferred embodiment of my invention; Fig. 2 is a rear end elevation thereof; Fig. 3 is a front end elevation; Fig. 4 is a sectional front side elevation; Fig. 5 is a section taken on line 44 of Fig. 4; and Fig. 6 is a detail view illustratingone manner of operation of the interconnecting swinging or rotatable throttle valves- A In its preferred form, herein shown and described, my invention comprises a main body 2 made preferably in a single casting and having an air inlet 3, an air chamber '8, 7

a Venturi tube 4 and a carbureting or mixengine comprises preferably a separate cast- 7 ing which, as shown in Fig. 3 may be bolted on the main body or otherwise secured thereto. The initial air chamber 8 is provided .with the usual spring controlled air valve 9 having a tapered coiled spring 10 "and an ad usting screw 11 for adjusting the tension of the spring of the air valve.

The air inlet 3 is provided with a nipple 13 connected in any suitable manner to a' Warm air stove (not shown) placed adjacent the exhaust pipe for the purpose of warming the initlal air entering the air chamber 8. In order to admit a certain amount of cold air when desired,a collar 12 is loosel mounted over the nipple 13 and is provi ed with an opening 14' adapted to register with a similar opemng in the nipple 13., By rotating the. collar 152 the proper cold air adjustment may be obtained, and I by means of the thumb screw 14 the collar 12 may be retained in any desired adjusted position. 1 i I The major part of the carbureting chamber is surrounded by two walls 15 and 16 forming a jacket, and walls l'fdivide the jacket into an upper compartment or heat-. ing chamber 18 and a lower compartment or reservoir 19. The compartment 18is formed with openings-20' and 21 for the purpose. of admiss on and discharge. of the exhaust gases of the engine thereby supplying heat to the compartment 18 and to the carburetor. I The lower compartment 19 form. a reservoir or bowl integral with the upper oompartment 18 and is designed for the purpose of storing heavier hydrocarbon fuels, such as kerosene. .Due to its "position and proxheat is absorbed b tube '55 spray nozzle 22 is connected to the three-way valve 23 provided with a suitable controlling lever 23'.

Located externally of the carburetor body are a plurality of float chambers, two being shown in the present embodiment. Float chamber 24 provided with an. intake pipe 26 'for gasoline is connected directly to the three-way valve 23 by means of a tube or pipe 28. External float chamber 25, used preferably for the storag'e of kerosene or other heavy hydro-carbon fuels and having the intake 27, is connected as at 30 by means of a tube or pipe 29 to the reservoir or bowl 19, thus supplying fuel thereto. From this reservoir a tube or pipe 32 conveys fuel directly to the three-way valve 23.

In order to change the height or position of the fuel level of the float chambers 24 and 25 with relation to the fuel jet 22, the floatchambers 24 and 25 are made vertically adjustable, this being accomplished in any suitable manner as by means of levers or other similar mechanical means.

In the present case, float chamber 24 is provided with a rod or link 33 secured to the coupling 33', the latter being connected to the tube 28 and the float chamber 24. The rod 33 is operated a vertical plane thereby to raise or lower the float chamber- 24 by any preferred means, such as by levers 34, 35, 36 and 37 (see Fig. 1), the operating lever 37 being pivoted to a bracket 44 supporting the same and adapted to cooperate for the desired adjustment with the graduated quadrant 38. Similar means are provided for adjusting float chamber 25 in a vertical plane as by means of the rod 41 attached to the coupling 41 and connected to levers 42 and 43. A suitable supporting means, as bracket 45, is provided'for supporting levers 33 and 41 and the remaimng operating mechanism connected thereto.

Although have illustrated the use of-a plurality of external adjustable fuel or float chambers with a multi-fuel car buretor, it is readily apparent that a single external adjustable fuel chamber may be em loyed if it is desired to use a'carburetor uti 'zing a single fuel, such as gasoline. I have found in practice that an external ad-- justable fuelor float chamber in any carbuthe particular use of the carburetor with one or more external adjustable float chambers, the operating means may be so positioned and arranged as to be within easy control of the operator.

In the present instance I have preferably employed a plurality of interconnected throttle valves, although if desired a single throttle valvemay be employed. The com- '1 mon outlet 7 is fitted with a primary throttle valve 50 preferably of the butterfly type and attached to a rotatable spindle 51 suitably journaled' in the casting, the outer end of which is connected to a suitable throttle 1e.- ver 52 by which the throttle valve 50 maybe opened and closed at the will of the operator. t

The main duct 5 is fitted with a secondary throttle valve 53 preferably of the butterfly type and connected to the primary throttle 50 by means of a link 54. Thus, the rotatable or swinging movement of valve 53 is valves ,are diflerently positioned or angularly located relatively to each other so that when valve 53 is completey closed, valve 50 is still partially open.

The fuel supply which is brought into contact with the air supply through the jet 22 located at about the apex of the Venturi tube 4 is sprayed into the air supply from inlet 3 and passes with the same through the ducts or tubes 5 and 6, forming an explosive mixture.

' As the fuel mixture-leavesthe spray nozzle the lighter portions thereof which vapor-' ize readily pass directly through the central tube or duct 5 while the heavier-portions thereof fall outward-.away from the mainstream and w are taken up through the auxiliary tubes or ducts 6. Thus the heating chamber which is'preferably cast integral with the mixing chamber and surrounds the same, furnishes a large heatin surface for the multiple ducts 5 and 6.

tral duct 5 and the lurality of smaller auxilia ducts 6, whic may be of any desired.

throttled conditions, and thus attain maxi-- mum flexibility of enginecontrol. This is y thus construct-- ing the mixing chamber with the main cen-.

further due to the fact that I provide means for varying the efi'ect/of the exhaust heating means in heating chamber 18 simultaneous] with the varying of the flow of gases throng 55 .ently adjustable float chambers it'is possible all of the ducts 5 and '6. Although by employing alone the multiple tubes or ductsof varying sizes, I am able to maintain a high verting the unmixed gases, or fuel and air,

to the points of highest temperature in the.

mixing chamber due tothe fact that the velocity of gases passing through the mixing chamber under such conditions is lowered,

and hence it is desirable to raise the temperature thereof. This additional means com rises the throttle valve 53 preferably of the utterfly type, which operates to divert the gases into the small ducts 6 which have greater heating surface.

Owing to the heated condition of the fuel reservoir 19 the latter is not equipped with a float for governing the fuel level due to the fact that whenthe fuel is in a highly heated condition it is turbulent and interferes with the proper functionof the float, and its operating mechanism. For this and other reasons I find it preferable to employ the externally located float chambers 24 and 25. f

Furthermore by-employing the exterior float chambers it is possible to make the same vertically adjustable preferably by means of levers as heretofore described. The operator therefore, may raise or lower either float chamber, which will have the effect of in:

creasing or decreasing the flow of fuel thru the spray nozzle 22.

- The rateof flowage varies according to the temperature to which the fuel is subjected, the rate of flow of gasoline increas ing approximately six. times between 40 and 170 F. At these temperatures the flow of kerosene is approximately proportionate,"

but since is necessary to brin this fuel to approximately 400, F. before it entersthe flue jet its fiowage must necessarily be enormously increased. I have found that a H single jet. having a non-adjustable fixed f opening, as well as a batteryxof, jets having fixed openings will' not practicably permit independent regulation of the gasoline and kerosene flow. g

By virtue of the separately and independoperating conditions w ich are distinctly adverseto proper fuel control and regulationin a carburetor of the ordinary type." Foamstance, in ascending grades or under similar overload conditions, it is desirable to tem-- porarily supply an increased flow ofj fuel,

- ling the -flow which can be readily done in my carburetor by raising the float chamber to raise the fuel ency for an over-rich mixture, the float chamber in my carburetor may be lowered, thereby decreasing the fuel flow thru the spray nozzle and in fact the lever 33 or 41 may be depressed sufliciently to cut off the fuel flow entirely, thus preventing fuel waste when coasting on long grades. Y Furthermore, under light loads or when'i ling, the float chamber may be lowered the eby decreasing the rate offuel flow, and preventing overrichness of mixture.

Although I have described a preferred embodiment of my invention, I desire it understood that I do not limit myself'to the exact details of construction illustrated and described, but .may make such vchanges and alterations as willcome within the scope of the appended claims.

I claim as my invention:

1. A carburetor comprising a mixing chamber, aheating chamber surrounding the same, said mixing chamber comprising a plurality of ducts, and means comprising a plurality of interconnected throttle valves for controlling the flow of gases through said ducts.

2. A carburetor comprising a mixing chamber, a heating chamber integrally surrounding the same, said mixing chamber comprising a main duct and a plurality of auxiliary ducts having a common outlet, 8. primary throttle valve for controlling the flow of gases through said common outlet, and a secondary throttle valve for controlof gases through said main ductv 3. A carburetor comprising a mixing chamber, a .heating chamber surrounding the same, said mixing chamber comprising a main duct and a plurality of auxiliary ducts having a common outlet, a primary throttle valve for regulating the flow of gases through said common outlet, and a secondary throttle valve for controlling the ow of" gases through said main duct and connected with said primaryjthrott'le valve.

4. A carburetor comprising'a fuel nozzle and a mixin ing a duct adjacent to and-alined with said nozzle, and oneor more auxiliary ducts for said nozzle, and means for heating the auxiliary duct orducts to a degree different from the main duct.

' 5. A carburetor comprising a fuel nozzle and a mixing chamber, the latter compris-- ing a duct. adjacent to and alined with said nozzle, and one or more auxilia ducts for said nozzle and smaller than sai first duct, and. means for heatin the auxiliary duct 3r. ducts to a degree di erent from'the main uct.

chamber, the latter compris 6. A carburetor comprising a mixing chamber having a plurality of passages terminating in a common outlet, heating means for said passages, means for regulating the flow of gases through the common outlet, and means controlled by said second means for automatically diverting the flow of gases from one passage to another thereby to increase the effect of said heating means.

7. A carburetor comprising a mixing chamber, a heating chamber associated therewith and having means for connection to the exhaust of the engine, said mixing chamber comprising a main duct and a plu rality of smaller auxiliary ducts all having a common outlet, a primary throttle for controlling the flow of gases through said common outlet, and a secondary throttle controlled by said primary throttle for regglating the flow of gases through said main not. i

8. A carbureting device comprising a mixing chamber, a plurality of compartments surrounding the same, means for connecting one of said compartments to the exhaust of the engine, a spray nozz'le, a plurality of float chambers, one of said chambers having connection to said spray nozzle, and another of said float chambers having connection to a compartment, .said last compartment also having means for connection to said spray nozzle.

9. In a carbureting device, a mixing chamber, exhaust heating means for the same, a fuel compartment efi'ectively associated with saidmixing chamber and heating means, .an external float chamber connected to said compartment for supplying fuel to the same, aspray nozzle, and external means for connecting said fuel compartment to the spray nozzle, said compartment beingso located as to absorb heat from said heating means and also to form a heating medium adjacent to said spray nozzle.

10. A carbureting device comprising a mixing chamber having a plurality of ducts substantially surrounded by a compartment connected to the exhaust of the engine, a

fuel compartment connected thereto, means for supplying fuel to said fuel compartment, a spray nozzle, means for connecting said fuel compartment to thespray nozzle, and means for diverting from one duct to another.

11. A carbureting device comprising a mixing chamber having a plurality .of ducts substantially surrounded by a compartment connected to the exhaust of the engine, a fuel compartment connected thereto, an external floa chamber connected to said fuel compartment, a spray nozzle, means for connecting said fuel compartment to the spray nozzle, and 'means for diverting the flow of gases from one duct to another and comprising an automatically controlled valve 10- catcd in one of said ducts.

12. A carburetor comprising a fuel nozzle and a mixing chamber, the latter comprising a duct adjacent to and alined with said nozzle, one or more auxiliary ducts for said nozzle, and means for varying the proportion of gases admitted in said ducts, and means for heating the auxiliary duct or ducts to a degree different from the main duct. (7

13. A self-contained carburetor comprising a casing having an air inlet and. havin within said casing a combined heating an mixing chamber comprising a plurality of independent passages all'within the heating chamber, saidchamber having a heat inlet, and said passages having a common outlet the flow of gases and a common inlet, a spray nozzle Within W said casing and adjacent to and communicating with said common inlet, means for conveyin fuel to the spray nozzle, means also wit in' said casing for varying the quantity of gases passing through one assage with relation to another passage, a cat containing kerosene chamber also within 8 said casing, and means for conveying kerosene from said chamber to the spray nozzle. Signed at 1822 Park Row Building, New York city, New York this 20th day of September 1920.

HARRY O. CRAM. 

